It is known to mount the voltage surge arresters by a reflow soldering technique on the printed-circuit board and to contact the other electronic components, such as PTC'S, varistors and diodes as chip components by means of a conventional clamping technique. Therein problems exist with the precise positioning of the voltage surge arrester, when the latter is not held in the desired position during the soldering process, and therefore contact problems or difficulties during further processing or assembly of the printed-circuit board may occur.
By various techniques of assembling different components on the printed-circuit board, several steps are required for contacting. Further, additional contact lugs are required for the assembly of the printed-circuit board with the other components (PTC's and varistors), thus increasing the material and manufacture costs.
In reflow soldering techniques it is common to apply solder material on the printed-circuit boards at positions intended for receiving an electronic component. Thereafter, the respective component is mounted on the solder material still being in a pasty condition, and then the completely assembled printed-circuit board is heated, until the solder material melts, and after cooling down, the electronic component is held in position by the re-solidified solder material and is electrically contacted.
As long as the solder material does not yet effect an intense connection of the electronic component to the printed-circuit board, that is immediately after placing the electronic components, the respective electronic component may slip and come out of the desired position. Since the reflow soldering technique is usually performed in continuous-heating furnaces, such as they are for example known from DE 40 16 366 C2, provisions have to be taken during transportation of the preassembled printed-circuit board, such provisions preventing the electronic component from slipping away from the desired position by movements or vibrations.
In order to prevent such slipping away, there is known for example from EP 0 540 497 A2 the utilization of a matrix which can however only determine the surface shape of the solder applied to the solder positions. Fixation of the component at least to a certain degree is not possible by this method. Positioning is to be facilitated by that the generated solder positions have a plane surface.
The utilization of an adhesive to fix the components to an printed-circuit board is disclosed in DE 41 26 913 A1. Therein the connection of the respective component to the printed-circuit board is established by an adhesive. Thereafter the actual soldering process is performed, and the complete connection is finally accomplished. In addition to the required adhesive, the supply of which necessitates higher expenditures for the printed-circuit board assembly, high requirements have to be met by the use of adhesive. Since the latter is exposed to high temperatures during soldering, it may come to damage the solder due to solvent possibly contained in the adhesive.